Marketable Securities (Tables)

12 Months Ended

Dec. 31, 2016

Investments Debt And Equity Securities [Abstract]

Summary of Cash Equivalents and Available-for-Sale Securities

The table below summarizes the Company’s cash equivalents and available-for-sale securities (in thousands):

			Gross		Gross
	Amortized		Unrealized		Unrealized			Estimated
	Cost		Gains		(Losses)			Fair Value
December 31, 2016
Cash equivalents:
Money market funds	$	18,992	$	—	$	—		$	18,992
Total		18,992		—		—			18,992
Available-for-sale securities:
Commercial paper securities		23,112		73		—			23,185
Corporate debt securities		10,005		—		(1	)		10,004
U.S. government sponsored entity debt securities		87,307		3		(25	)		87,285
Total		120,424		76		(26	)		120,474
Total cash equivalents and available-for-sale securities	$	139,416	$	76	$	(26	)	$	139,466
December 31, 2015
Cash equivalents:
Money market funds	$	25,070	$	—	$	—		$	25,070
Commercial paper securities		2,000		—		—			2,000
U.S. government sponsored entity debt securities		38,866		1		—			38,867
Total		65,936		1		—			65,937
Available-for-sale securities:
Commercial paper securities		30,667		50		—			30,717
Corporate debt securities		17,275		—		(12	)		17,263
U.S. government sponsored entity debt securities		91,562		—		(24	)		91,538
Total		139,504		50		(36	)		139,518
Total cash equivalents and available-for-sale securities	$	205,440	$	51	$	(36	)	$	205,455